Process of obtaining butyl alcohol and acetone by fermentation



Patented Sept. 19, 1933 PATENT oFFicE 1,927,814 c PROCESS OF OBTAINING BUTYL ALCOHOL AND Ao 'ro E BY FERMENTATION David Alliston Legg, Terre Haute, Ind., assignor to Commercial Solvents Corporation, Term Haute, Ind., a corporation of Maryland No Drawing. Application November "26, 1928 Serial'No. 322,098 a} llClaims. (01. 260-135) In the past it has been the custom to carry out the butyle'acetonic fermentation somewhat as 10 follows; Cereals such as maize, kaffir corn, wheat, oats, etc., have been ground to a fairly coarse meal and the bran removed. In the case of maize, it is the'custom also toremove the germ during this stage of the treatment. Suflicient of this meal isthen added to water to give a concen- I tration of approximately 7% by weight and the resulting mash subjected to a suitable cooking for thepurpose of thoroughly sterilizing the material and at the same time breaking down the starch particles into a form more easily acted upon by micro-organisms. The sterile mash thus'ob-' tained, is cooled to approximately 97 F., inoculated with a culture of butyl alcohol-acetone ore ganism and allowed to ferment. At the end of the'fermentation, the products formed may be separatedand recovered by fractional distillation or other suitable means. v

C'lostridium acetobutylz'cum, (Weizmann) and certain otherforms' of butyl alc ohol-acetone-f' forming organisms readily act upon carbohyev drates; Still other organisms forming, these products require that the carbohydrates or pro-' teins be previously hydrolyzed before they are able to satisfactorily carry out the desired fermentation process. When a, carbohydrate such as maize, wheat or other cereal is used as the raw material, as a rule, sufficient nitrogenous and other required nutrient materials are present to insure a satisfactory fermentation. However,

40 when other carbohydrates such as cassava or saccharine materials such as black strap molasses, I-Iydrol, wood sugars or pure sugars are used, satisfactory results are usually not obtained without the addition of nutrient materials." For this reason, in order to obtain uniform results,

it iscustomary when fermenting saccharine ma-i terials to use the latter with a major portioniof' maize meal or of similar material which con-' tains a suflicient quantity of naturally occurring nutrient material to enable the entire body of material to be fermented. j

I have now found that a more complete utili zation of carbohydrate materials such as maize,

rials are subjected to a preliminary treatment ent mat'erial.

wheat, oats, etc., may be obtained if these mate-1 the beneficial effects may be due largely to a more which apparently converts aportion of thev carbohydrate into a form more read l acted upon by the bacteria, the operation being carried out in such amanner as nottorequire any separation 5 or losses ,of the valuableraw materials. In a process of this character where the cost 'oftthe raw material is suchan'importantfactor," the small but relatively important saving efiected'by my new process marks an importantstepfor ward in the industry... I Q j I am aware of the fact that in the past it has been suggested that the starchof maize be conv verted entirely into maltose and dextrose by treating the former with diastase'obtained by soaking or steeping the hull or bran of such 7 cereals. According-to the concept of my invention, however, it is neither necessary nor desirable' that the carbohydrate be converted entirely into saccharine material. My'process of effecting the desired degree ,of conversion is also much more. simple and requires lesssupervision and care than in the caseof previously disclosed processes.

In carrying outniynewf process I prefer to proceed-somewhat as disclosed below, but it is dis-' :tinctly understood, however, that the methoddescribed is cited only as an example, and that my j invention isintended to coverthe various modi fications that would naturally occur toone skilled in the art. The raw material to be used in the" fermentation-such as maize- -is placed in a suit- 8 able'vessel, covered with water and allowed to steep or soak at a temperature ranging say from 45 'C. to "approximately C. for a length-of time depending upon the material employed, the form in which the material is steeped, the particular [treatment to which the material is later :tof'be subjected, andother factors. It is generally preferred to steep the material for a period of 48 hours and at a temperature of approximately 60? C. During the course 'of' this 9 steeping process some action oractions, the exact character of which I am not certain, take place with theresult that when'th'e material I is later" subjected to fermentation somewhat higher yields are obtained than from similar material which has not been'treated in this manner. There is a possibility that this beneficialefiect may be due, to the conversion of a portion of the pentosans, j hemicellulose and starch into a form more easily or more completely acted upon by the microorganisms. Still another possibility is that there may be a slight hydrolysis of the proteins resulting in the fermentation of a more effective nutri- According to;still another theory,

be ground and used without removing the germ.

If preferred the material may first be groundand the meal thus obtained subjected to the steeping "operation, either with or without removal o'fthe germ. H

Whatever preliminary treatment is made use of, the material at'the conclusion o'f the' steeping process is converted into a coarse meal made up into a mash of approximately 5%-9% concentration by weight with water, thoroughly sterilized, cooled to approximately 97F.',"in-

oculatedwitha culture of clostridz 'um acetobutylicurnftwei'zmahnl brother butyl alcohol-acetone forming. trgamsmja e "allowed "to I ferment at abogtp'pi' Thesmvents formed may then 'be but'yl' 9.10 2101; acetone and 'ethyl alcohol are pro-'- ducediin. approximately the ratios of 6:3 1. In

makingfup thefma'sh it is possible also to substitute 'i'for 1a pa'rt'or allo'f the water the"steep'"f water obtaineda's previously described;

In. the table whichfollowsf'data are given" showmgthe' results obtained when carrying out my process under slightly different conditions.

Table I Conditions of Yielddof sgv nts steepmg on ry asls Peycent 2 i m- N o J Material 7 Tem I U t l d are I Time ny1e 2352 P steeped 0. Per cm Per bent 1 Who1'e'maize 48 60 i 27. 5 26.3 1. 3' 2 Whole maize. 48 60 28. 2 27. 2 1.0 Whole maize. 48 60 26.8 25. 9 0. 9 4 24 60 26. 6 24. 0 2. 6 5 48 y 45 26.9 26.1 0. 8 6 48 60 26. 5 26.1 0. 4' 7 Whole maize-." 48 75 26.7 26. 1 0.6 8 .Degerminated I maize meal.-- 48 60 27. 8 27. 0 0.8

In' a ry-15g out m new process,'it is distinctly 1 understood that I do not restrict myself to the conditions outlined above but desire toclaim oats,, barley, kafiir corn, etc... The length of steeping time may also be'varied somewhat'both above and below the limits disclosed in the table above;but I have found that in 'most cases the optimum; commercial results are obtained by steeping for- 24 -48 hours. Longer periodsof time increase the cost of the final products somewhat due to the length of time the material is-in process- Also, if the material is to be laterdegerminated, greater difficulty is experienced if the material is steeped too long. As has been T pre'viously indicated, the temperature at which the steeping may be effected may. be varied over a fairly wide range. While temperatures both below .and above the range specified above may be .e1np1oyed,-I, prefer to operate within this -low 45 0. leads to the incubation of undesirable acetone and ethyl peratures as high as 100C. with a fair degree of success. 'While I have only described the use of Clostridium acetobutylicum (Weizmann), it is distinctly understood that my improved process applies equally well to other organisms which havebee'n recommended for the production of but-yl alcoholand acetone,'such as B. butyZ-aceticum,""B-butylicu'mtB. F., B. granulobacter pectinovorum', etc.

Now having described my invention, what I 1. A fermentation process which comprises water-steepingsubstantially starchy carbohydrate-containing material at temperatures rang-. 5

'ing fromabout 45%0 'about 75" c. for 24420 48" 'hours, sterilizing the mash pro'duced' 'fromfiaid water-steeped carbohydrate material, inoculating" I fermentation to proceed; and recovering'normal butyl alcohol; acetone and ethyl "alcohol' f the-fermented mash. r

2". A fermentation process which consists' in?) water-stee in substantially starchy E'arbohyJ drate containing materials'at temperatures rang ingfrorh about-45 to about75'C.for'24to48 hours, sterilizing" a mash "producedfroni *sa" water 'steep'ed carbohydrate material,"inoculating the [mash with butyl-ac'eton'ic bacilli; aunt/mg ferrnentationto" proceed; and recovering"nrbutyr alcohol; acetone andethyl alcohol froirifthe fei-'"' mentedmash'. 1 I

3. A "fermentation procs'siwhich' consistsunfifl water steeping"'maizeat'a temperature ranging"f from about 45 'to about 75 0. for 24 to'4s'1idurs; j

sterilizingthe "mash produced "from "said "ware-1 steeped. inoculating"thmaSh"with butyl acetoni'c' bacilli, allowing rer'mentationi to i pro 'ceed', and "re overing h-butyl a1c'6ho1,acetone?" 5.;

andethyl'ialcol'iol' from the 'feririent'ed'inash'. j 4. "A' fermentation process" which *consis't's' in water-steeping maize meal at t mperaturesra g; ing'frm about '45? to about 75 'CJjfOI'f '2412048" I hour'sfstlilfzillg 15116 maTSh produced [from Saiid water-steeped maizeineal',"inoculatingth'e ma n 'wf with "butyl ac'etonic"bacilli; auowing ferment tion" to proceed;and"r coveringin-butyl' alcono amohoIrrom the" fermented? mash 1 7 I 5. A fermentation" process which"consists"in"' watersteeping degermiriatedm'aiz'e "attemper' V bulf s ranging f IOfI'l' abOlIt45 tUaDOllt 75 CffO T 24 to 4'8 hourssterilizin'gthe'mashproduced'froifij said water-steeped 'degermmated marzeyino cumte 6. "In, a process for'the production cf' n-but li alqonoigacetcne and ethyl alcohol," the step'which comprises 'wate'r' -steefping' suitable" substantially starchy" ""carbohydratewontaining material at temperatures below 100 C.but in'eXcess'of 'nor mal atmospheric temperatures f 01 2a to "18 hours previous" to inoculatingTwith butyl-acetonid bacilli the mash prepared 'froms'aidjmateriallf '2. In ai'proc'ess forthe production ofin-butyl' H alcohorfacetone' and ethyl "alcohol, the step which comprises "water-steeping maize" at temperatures" below 100C. but iniexcess or normalatniosph'eri'c I heating substantially starchy carbohydrate-contemperatures for 24 to 48 hours previous to inoculating with butyl-acetonic bacilli the mash prepared from said material.

8. In a process for the production of n-butyl alcohol, acetone and ethyl alcohol, the step which taining material for 24-48 hours in an aqueous medium at temperatures between atmospheric and 100 C., sterilizing the mash thus produced, inoculating said mash with butyl-acetonic bacilli,

' allowing fermentation to proceed, and recovering normal butyl alcohol, acetone and ethyl alcohol from the fermented mash.

11. A fermentation process which comprises heating substantially starchy'carbohydrate-con- Y taining material for 24-48 hours in an aqueous medium at temperatures from 45-75" C., sterilizing the mash thus produced, inoculating said 1 mash with butyl-'acetonic bacilli, allowing fermentation to proceed, and recovering normal butyl alcohol, acetone and ethyl alcohol from the fermented mash.

DAVID ALLIs'roN LEGGQ 

